Speedometer



.June 6o, 1966.. R, Q, HELGEBY 2,646,166

' SPEEDOMETER Filed Jan. 2, 1932 2 Sheets-Sheet 1 gmc/nto@ June 30,.1936. R. o. HELGEBY SPEEDOMETER Filed Jan. 2, '1952 2 Sheets-Sheet 2awww Patented June 30, 1936 UNITED STATES PATENT OFFICE BPEEDOMETERApplication January 2, 1932, Serial No. 584,369

2 Claims.

This invention relates to measuring instruments and has been designed asan improvement in a combined speed and distance-recording instrument forvehicles.

An object of the inventionis to lprovide such an instrument with animproved main frame.

Another object is the provision of an improved spindle-supporting frame.

As another object the invention provides a novel driving mechanism fromthe rotor shaft to the odometer mechanism.

Still another object is the provision of a main frame adapted for usewith a stationary magnet or witha rotating magnet.

Other objects and advantages will appear from the following description.

Accompanying the description' are drawings in which- Fig. 1 is a lviewin front elevation partly broken awayl of my improved instrument.

Fig. 2 is a section on line 2-2 of Fig. 1.

Fig. 3 is a section on line 3-3 of Fig. 2.

Fig. 4 is a section on line 4-4 of Fig. 2.

Fig. 5 is a view in perspective of the main frame.

Fig. 6 is a perspective of the spindle frame.

Fig. 7 is a perspective of the magnet with the temperature compensatorassembled therewith.

Fig. 8 is a view partly in side elevation and partly broken away and insection of a modification using a rotary magnet instead of the fixedvmagnet used with the form of the invention shown in the other figures.

Fig. 9 is a view as seen from line 9-9 of Fig. 1.

Fig. 10 is a perspective of a compensator.

Referring by reference characters to the drawings, numeral 9 representsthe main frame, this frame being preferably formed by die casting. Thepresent invention is largely concerned with an improvement in this mainframe. In the past such frames have been made of cup shape forsupporting a magnet and with an axial aperture in the bottom of the cup"for the rotor shaft. The rotation of this shaft rotates the rotor memberrelatively to the magnet. With such prior main frames there has beenassociated a stamped frame carrying odometer wheels and having an armoverlying the instrument provided with a bearing in axial alignment withthe rotor shaft, this bearing cooperating with a bearing at the end ofthe rotor shaft for the spindle of the speed indicator mechanism. It hasbeen found that it is better to support the shafts for thedistance-indicating mechanism on parts of the die cast frame rather thanon the separate stamped frame as heretofore. When so supported there maybe used alight and inexpensive stamping to carry the upper end of thespindle and to assist in maintaining the position oi the transfer pinioncarriers associated with the odometer. It has been found, too. that themain frame can readily be made for use with either a ilxedly mountedmagnet or a rotating magnet.

'I'he cup-shaped main frame 9 has a base Il and an annular wall i3. Fromthe base there 10 projects axially a shank i5 externally threaded as atI1. The shank is bored out at i 9 to provide a rotary bearing for therotor shaft 2|. The frame 9 has a plurality of rearwardly-directedbosses 23 apertured for receiving fastening means 15 25 by which theframe 9 is clamped to the casing 21. The front opening of the casing iscovered by a dial 29 and a glass 3|, these parts being held in positionby a securing ring 33. From the main frame there also projects a secondshank as shown in Fig. 1 and Fig. 5. This shank 35 is apertured toreceive the reciprocably and rotatably mounted reset stem 31. The latteris held outwardly in itsinoperative position by a spring 39, this springengaging the end of the shank 35 and a suitable abutment on the stem 31.Within the instrument the stem 31 is provided with a cone 4i and apinion 43, as usual.

Within the hollow chamber of the frame 9 is an inner shoulder 45 and anouter shoulder 41. these shoulders being circular in form. Upon theshoulder 41 in the form of the invention employing a fixedly-positionedmagnet there is placed a C-shaped magnet 49. Within the gap of themagnet is placed a temperature-compensating device 5i. This is a stampedpiece of the well-known nickel alloy commonly used for this purpose. Itis shaped as best shown in Fig. 1, and it is dimensioned to convenientlysnap into position between the poles of the magnet.

The main frame has apertured ilat faces 53 upon which rest the radialslotted tongues 55 of the spindle frame 61. This spindle frame alsorests on ledge 58 and is held by fastening means 59 extending throughthe slots of the tongues and into the apertures of the faces 53. Underthe heads 9| of fastening means 59 are angular clamps 63, the ends ofwhich extend through slots 82 oi' the spindle frame and engage and holdthe magnet 49 on its seat 41.

At 65 is a substantially conventional rotor on the inner end of therotor shaft 2|. The rotor may be conveniently secured in position byforming the shaft with a reduced end and seating the rotor thereon andturning the metal at the end a suitable bearing 1| for the end of aspindle 13 extending in the same axial direction as the rotor shaft. Adisc 15 oi' aluminum or the like is secured to the spindle 13 betweenclamps 11. To

provide the other bearing for the spindle 13 the spindle yframe v51 isused. Upstanding from its fiat base portion 19 is an arm 8| having itsend bent'at an angle substantially into parallelisnr with the baseportion 19. This arm is apertured as at 85 to carry the bearing 81 forthe spindle 13 j arm' 12 with the part 83. The spindle 13 extends asshown in Fig. 2. Rotatably surrounding the upper end of this bearing isa tension-adjusting arm 12. One end of the arm 12 is connected to a zerobiasing spring 14. The other end of the spring 14 is connected to thespindle 13. The arm 12 extends radially to a position over a bridgeportion 16 of a side wall 93 to be referred to below. The arm. 12 has alateral extension 89 which is bent over the end 83 to yieldingly engagethe under side thereof, so that the spring adjustment is maintained bythe frictional engagement of the through the dial plate 29 and to itsend there is fixed a pointer 90. This assembly of parts including thedisc 15, spindle 13, and the pointer is rotatable under the influence ofeddy currents set up in the disc 15 under the influence of the magnetand rotating rotor in a manner well understood. 'I'he dial plate Willbeprovided with suitable characters whereby the extent of rotation of theneedle may be measured. The rotor shaft is to be connected by means of aexible cable by some shaft, the rate of rotation of which v varies withthe rate of travel of the vehicle so that the position of the needle onthe dial measures the speed of the vehicle as is usual in suchinstruments.

The main frame is formed with opposite arms 9| and 93. These arms aresubstantially parallel and are at right angles to a diameter of the cup.Arm 9| has three vertically-disposed openings 95, 91, 99. Arm 93 hasapertures i0i and |03. The apertures and |01 register for the support ofa shaft |05. This shaft carries a series of odometer wheels |01 of whichthe right-hand wheel |01 may be a wheel without characters. The wheel|01' is formed rigidly with a worm |09 and a gear I I. Between each twoadjacent odometer wheels |01 is a disc H3 carrying a transfer pinion H5whereby the next higher denomination wheel is driven by the wheel ofnext lower denomination. Each disc i i3 has a radial extension I i1entering a slot il 9 in the base 19 of the spindle frameV 51. In thisway the discs l I3 are held from rotation to the end that the transferpinions may function as intended. A gear I2i is rotatably supported by apin carriedV in opening 91. This gear I2| engages gear III as shown inFig. 1. Gear |2| also engages a gear |23 rotatable about the axis of ashaft |25 supported in openings 99 and |03. Rotatable about the axis ofshaft |25 are other iigure wheels |21, these wheels constituting theso-called trip set. These wheels also are separated by discs II3 as inthe case of the iirst set of wheels. The discs H3 as. before are for thepurpose of carrying transfer pinions and are held from rotation byradial extensions ||1 entering a slot of the spindle frame, this slotlike the other being represented by numeral H9. Adjaaccesos cent gear|23 and rigid therewith is a gear |28. Aconical member |3| is rigid withthe gears |23 and |28, and the cone and gears are connected by a sleeve|30. This assembly is at all times non-rotatably connected to the rst ofthe 5 figure wheels |21 but is slidable onv the shaft |25 relatively tothe ilrst wheel. 'Ihe assembly is normally held by a spring |33 towardthe right (Fig.

1) so that gear |23 normally meshes with gear |2I. The assembly may bemoved to the left by 10 an inward reciprocation of stem 31, thismovementto the left being effected by the engagement of parts 4| and |3I. Afterbeing s o moved the gear |29 is engaged bythe pinion 43 and rotation ofstem 31 will then function to rotate the wheels 15 of the trip set.Clips |32 engage over the arm 83 adjacent the ends of the shafts |05'and |25. They enter grooves |34 and engage the shafts, serving -to holdthem against'reciprocation.

The odometer is normally driven by a plurality 20 of shafts rotatablysupported in the main frame 9. The series of shafts takes the power fromthe rotor shaft and delivers it to gear |09 of the season set of wheelswhereupon the gears ||I, 2|, and |23 transmit'the drive to the trip setof 25 wheels. Adjacent the junction of the base of the cup of the mainframe and the shank I5, the frame is provided with a bore |35 throughwhich extends the second worm shaft |31 driven by the rst worm |39 onthe rotor shaft. 'This second worm 30 shaft |31 is geared to a thirdworm shaft |4| supported in bearings |43 and |45. This third worm shaft|4| engages the so-called fourth worm, the gear |09 which is rigid withwheel |01'.

The apertures |41 and |49 in lugs 15| and |53 85 respectively are toreceive rivets |55 securing retaining means |51 to prevent amai movementof the shafts |31 and |4I.

Preferably there will be used an angular calibrating member |59 in theform of the invention employing the iixedly-mounted magnet. This angularcalibrating member |59 is pivoted to the main frame at ISI for rotationto adjustably po-v sition an arm of this member relatively to themagnetrpoles. As seen in Fig. 1 this arm extends under the bridgeportion 16 which connects the end portions of the wall 93. The stampedspindle frame is recessed as at |60 to accommodate the necessarymovements of this calibrating arm.

Fig. 8 shows how the main frame may be employed without change for usewith a rotating magnet. In this case a bar magnet I 65 is provided withup-turned ends as shown. The middle point of the bar is secured to theend of the rotor shaft 2|' which extends through the shank I5 ,of themain frame 9. An inverted cup-shaped field plate |61 is used toconcentrate the influence of the magnet upon the drag disc. The openedge of the cup rests on shoulder 45 and the cup is held in position byfastening means 53' and 59', these parts corresponding in general to 63and 59 of the form already described. Under the heads of the fasteningmeans 59 is secured the spindle frame 51' corresponding to 51 of Fig. 6.65 Between the magnet |65 and the cup-shaped field plate 61 is aninverted cup-shaped drag disc |69. This drag disc is secured to aspindle 13. 'Ihe mounting of the odometer and the drive for the odometeris substantially as in the form described 70 above. It will therefore beseen that with the two frames-the main frame of Fig. 5 and the stampedframe of Fig. 6-it is easily possible to build the-now preferred fixedmagnet type of instrument or the rotary magnet type. 75

' 'amazes lof the other form. It supports the odometer shafts and alsoprovidesrotary bearingl supports for the odometer driving shafts. Theso-called spindle frame which lis amV inexpensive casting functions tohold the outer end of the drag disc spindle and. by means of slots, torestrain the transfer pinion carriers from movement from their operativepositions.

I claim:

1. In a magnetic measuring device, a main frame having an axial passagefor a rotor shaft and a shoulder to support a magnet. a rotor shaft.

, y 3 a magnet supported on said shoulder. said main frame having anaxial wall with an aperture therethrough, a. second frame having a flatbase and an upwardly and inwardly directed part tov overiie the axisofthe rotor shaft. fastening means to clamp `said. frame in assembledrelation and to hold the magnet on the supporting shouif der, andavcalibrating member hinged to said axial wall and extending throughsaid aperture in the axial wall to a position adjacent the poles of themagnet. y

2. 'Ihe invention defined by claim 1 together with a resilientthermo-sensitive compensator held by its own resiliency between thepoles of RALPH o. messy.

. the magnet.

